The Eight-Circuit Model of Consciousness is a hypothesis proposed by Timothy Leary and expanded on by Robert Anton Wilson and Antero Alli as well as Laurent Huguelit. The model describes eight circuits of information (eight "brains") that operate within the human nervous system, each corresponding to its own layer of the direct experience of reality.

Four of these, called the "larval circuits" and the "lower" set, deal with normal psychology. The other four are proposed as being "higher", and called the "stellar circuits". This latter group deal with altered states of consciousness, such as enlightenment, mystical experiences, psychedelic states of mind, and the authors even claim psychic abilities. The hypothesis proposes that these altered states of consciousness are recently evolved, but not widely utilized. Leary describes the four "larval circuits" as necessary for surviving and functioning in a terrestrial human society. Leary proposed that the "stellar circuits" will be useful for future humans who might someday migrate to outer space and live extraterrestrially.

Leary, Alli and Wilson have written about the model in depth and how each circuit operates, both in the lives of individual people and in societies.

The term "circuits" came from the first wave of cybernetics research and development in the United States in the 1970s. (Others have proposed that the term "systems" should be substituted for "circuits" to reflect both a systems theory approach and also the changing anatomy of an entity as it goes through a neurological change).

This circuit is activated in adults by opioids such as morphine and heroin. This circuit begins with 1 spatial dimension, forward/back.

This circuit is imprinted early in infancy. The imprint will normally last for life, unless it is re-imprinted by a powerful experience. Depending on the nature of the imprint, the organism will tend towards one of two basic attitudes:

A positive imprint sets up a basic attitude of trust. The organism generally considers the environment benign and accepts and approaches. This is equivalent to a default life position of 'you're ok' in the 'life positions' model of Transactional analysis.

A negative imprint sets up a basic attitude of suspicion. The organism generally regards the environment as hostile and flees and avoids. This is equivalent to a default life position of 'you're not ok' in the 'life positions' model of Transactional analysis.

This circuit is said to have appeared in the earliest evolution of the invertebrate brain and corresponds to the reptilian brain of triune brain theory. This circuit operates in essentially the same way across mammals, reptiles, fish, primates and humans.

This circuit is imprinted by human symbol systems. It is concerned with language, handling the environment, invention, calculation, prediction, building a mental "map" of the universe, physical dexterity, etc.

Robert Anton Wilson, being heavily influenced by General Semantics, writes of this circuit as the 'time-binding circuit'. This means that this circuit's contents – including human know-how, technology, science etc. - are preserved memetically and passed on from generation to generation, constantly mutating and increasing in sophistication.

This fourth circuit is imprinted by the first orgasm-mating experiences and tribal "morals". It is concerned with sexualpleasure (instead of sexual reproduction), local definitions of "moral" and "immoral", reproduction, rearing of the young, etc. The fourth circuit concerns itself with cultural values and operating within social networks. This circuit is said to have first appeared with the development of tribes. Leary never associated a drug with it, but some have pointed out that entactogens such as MDMA seem to meet some of the requirements needed to activate this circuit.

This is concerned with neurological-somatic feedbacks, feeling high and blissful, somatic reprogramming, etc. It may be called the rapture circuit.[5]

When this circuit is activated, a non-conceptual feeling of well-being arises. This has a beneficial effect on the health of the physical body.[6]

The fifth circuit is consciousness of the body. There is a marked shift from linear visual space to an all-encompassing aesthetic sensory space. Perceptions are judged not so much for their meaning and utility, but for their aesthetic qualities.[7] Experience of this circuit often accompanies an hedonistic turn-on, a rapturous amusement, a detachment from the previously compulsive mechanism of the first four circuits.

This circuit is activated by ecstatic experiences via physiological effects of cannabis, Hatha Yoga, tantra and Zen meditation. Robert Anton Wilson writes, "Tantra yoga is concerned with shifting consciousness entirely into this circuit"[8] and that "Prolonged sexual play without orgasm always triggers some Circuit V consciousness".[9]

Leary describes that this circuit first appeared in the upper classes, with the development of leisure-class civilizations around 2000 BC.

Note: Timothy Leary lists this circuit as the sixth, and the neurogenetic circuit as the seventh.[10] Robert Anton Wilson reverses the order of these two circuits,[11] so that the neurogenetic circuit is the sixth and the metaprogramming circuit is the seventh.

This circuit is concerned with re-imprinting and re-programming all earlier circuits and the relativity of “realities” perceived. The sixth circuit consists of the nervous system becoming aware of itself. Leary says this circuit enables telepathic communication and is activated by low-to-moderate doses of LSD (50-150 µg), moderate doses of peyote, and psilocybin mushrooms. This circuit is traced by Leary back to 500 BC.

This circuit is the connection of the individual's mind to the whole sweep of evolution and life as a whole. It is the part of consciousness that echoes the experiences of the previous generations that have brought the individual's brain-mind to its present level.

Although Leary propounded the basic premise of eight "brains" or brain circuits, he was inspired by sources such as the Hinduchakra system.

His most direct inspiration was received in the form of a document from a student of yoga, a pamphlet containing 24 different pages, with three-page subdivisions each corresponding to a particular yogic "energy".[15] Leary then translated this and expanded it into a 24-stage model of evolution, and eventually streamlined it into the eight-circuit model of consciousness. With this, Leary created his umbrella model which others have expanded on.

As one grows from infancy, the circuits are activated in turn, as described by Jean Piaget. Leary thought that the first four circuits reside in the left hemisphere of the brain or the cerebrum. The later four were said to reside in the right hemisphere.

An under-utilized “lower” circuit hinders the complete expression of a “higher” circuit. It would thus become necessary for a person to fully experience, integrate, and embody the survival circuits, in order to withstand the shock that accompanies the activation of the post-survival circuits.

Leary claimed that among other things this model explained the social conflict in the 1960s, where the mainstream was said to be those with four circuits active and characterized by Leary as tribal moralists and clashed with the counter-culturists, who were then said to be those with five or more circuits active and characterized as individualists and hedonists.

Leary's first book on the subject, Neurologic, only included seven circuits when it was published in 1973. Exo-Psychology, published in 1977, expanded the number of circuits to eight and clarified the subject; it was re-published as revised by Timothy Leary with additional material in 1989 under the title Info-Psychology (New Falcon Publishing).

Leary theorized that until recently in human development these higher circuits have remained dormant within the brain.[citation needed].

The model is fairly prominent in chaos magic. This concept has been detailed in "Chaotopia!" by Dave Lee, a leading member of the magic society Illuminates of Thanateros. Although both Leary and Wilson were members in this group near the end of their lives, the circuit design clearly predates this organization.

Angel Tech by Antero Alli, is structured around the eight-circuit model. In the book, the first four circuits are associated with robotic ("tech") aspects of humanity, and the final four are related to the "angelic" nature. It includes suggested activities such as meditations and construction of tarot-card collages associated with each circuit.

Bruce Scofield has written about the correlations of the mode with astrology. Resonances between planetary cycles and the birthday are suggested to be triggers that open temporary windows of imprint vulnerability. The Moon is correlated with the biosurvival period, Mars with the emotional-territorial stage, Mercury with the rational mind and Venus with the socio-sexual stage. These are initiated respectively at birth, at the second birthday, at age 3.5 and age 8 at which times the Moon, Mars, Mercury and Venus return to their birth positions, or are in phase with it. The other four circuits are considered octaves of the first four.[18]